Practice firearm



Nov. 16, 1965 R. w. KERR 3,217,441

PRACTICE FIREARM Filed May 7, 1964 IN VEN TOR.

3,217,441 Patented Nov. 16, 1965 tice 3,217,441 PRACTICE FIREARM Raymond William Kerr, Box 4178, Lincoln, Nebr. Filed May 7, 1964, Ser. No. 365,701 4 Claims. (Cl. 42-77) The present invention relates generally to firearms and ammunition and more particularly to firearms intended for training and practice use and ammunition of the safety type for use therein.

There is always the possibility in target practice with firearms, even if safety type ammunition is intended, that a standard or conventional round might be loaded into the firearm by mistake and fired. This is dangerous and is not unlikely to cause serious injury and even death. Yet it is desirable that firearms used for practice purposes be comparable in size, weight and balance with those using conventional ammunition.

Accordingly, it is a general object of the present invention to provide safety firearms and ammunition which are effective for training and practice purposes but which are selective in that the firing only of the safety ammunition is permitted and the firing of standard or conventional ammunition is precluded.

It is a more specific object of the present invention to provide a safety round of ammunition which is not only readily distinguishable from a conventional round but the use of which requires the firearm to be selective to the extent that it can fire only the safety round.

A related object is to provide la safety firearm construction for receiving and firing a safety round, but which will not fire a conventional round that might be inserted therein accidentally.

It is a further object to provide an adapter for selectively converting a standard firearm for practice use with safety ammunition so that it can re only safety rounds when so adapted, but which adapter can be readily removed to permit restoration of the firearm to its normal operating condition.

Other objects and ancillary advantages of the invention will be apparent from the following detailed description and upon reference to the accompanying drawings, in which:

FIGURE 1 is a side elevation partly in section of a safety firearm loaded with a safety round of ammunition embodying the present invention.

FIG. 2 is a fragmentary section of the firearm of FIG. l but having a round of conventional ammunition inserted therein.

FIG. 3 is an elevational view partly in section of a standard revolver converted in accordance with the present invention so as to be capable of firing only safety ammunition.

FIG. 4 is a side elevation partly in section of a round of safety ammunition showing the cartridge and projectile separated; and

FIG. 5 is a rear elevational view of the round of safety ammunition shown in FIG. 4.

While the invention is described in connection with certain preferred embodiments, it will be understood that it is not thereby intended to limit the invention to those particular embodiments. On the contrary it is intended to cover all alternatives, modifications, yand equivalents which may be included within the spirit and scope of the invention as defined in the appended claims.

Referring more particularly to the drawings, there shown in FIG. 1 is a pistol type firearm 10 and a safety cartridge 11 embodying the present invention. The illustrative firearm 10 is intended for training and practice use and includes a frame 12 pivotally mounting a forwardly extending barrel 14 and having a depending stock or grip 15. As shown the firearm frame 12 and barrel assembly 14 :are made of a suitable plastic material with the barrel being reinforced with a metal liner 16. A firing chamber, generally indicated at 18, is provided to receive the cartridge 11. The chamber 18 includes the rear portion of the barrel assembly 14 and its liner 16. The rear of the firing chamber 18 is defined by a recoil plate 20 which is carried by the frame 12.

The firearm 10 includes a firing mechanism for detonating the round 11. In the illustrative firearm the firing mechanism includes a firing pin 22 which is mounted upon a carrier 24 for longitudinal movement between cocked and firing positions. In the latter position the firing pin projects through an opening 25 in the recoil plate 20 so as to engage and detonate the primer of a safety round 11 that is disposed within the firing chamber 18. The instant firing mechanism is shown merely for purposes of illustration and it will be apparent that any number of operable constructions can be used. In the illustrative firing mechanism the firing pin carrier 24 is longitudinally movable within a bore 26 formed in the upper rear portion of the frame 12. The carrier is biased toward firing position by means of a main spring 28. The main spring is compressed by manually withdrawing a cocking pin 29 which has a crosshead 30 at its forward end that is engaged in a slot 31 formed in the firing pin carrier 24. Upon withdrawing the cocking pin, the crosshead 30 engages the rear end of the carrier slot 31 so that the carrier is pulled rearwardly within the bore 26, compressing the spring 28 and withdrawing the firing pin 22 in the aperture 25 in the recoil plate 20. Withdrawal movement is continued until the cocked position of the firing pin carrier 24 is attained. To retain the carrier 24, and with it the firing pin 22, in cocked position a spring biased pawl 33 is provided for engagement in a notch 34 located adjacent the front end of the carrier 24. The cocking pin 29 is equipped with a light return spring 35 which, as shown, is disposed within the main spring 28 and about the cocking pin. The return spring is also compressed as an incident to withdrawal movement of the cocking rod. When the cocked position of the carrier is attained and the cocking pin is released, the return spring, which at its forward end engages the crosshead 30, serves to retract the cocking pin.

To release the carrier to the action of the main spring the frame is equipped with a trigger mechanism. This mechanism includes a trigger 36 which is mounted at the forward end of a slide 38 the latter being biased toward normal forwardly-extended position by means of an eX- pansion type spring 39. The trigger slide 38 is formed with an inclined rib 40 and interposed between the rib and the pawl 33 is a push rod 41. The lower end of the push rod is complementally inclined and in engagement with the rib 40. Thus, when the trigger 36 is moved rearwardly upon being squeezed by an operator using the illustrative firearm, the slide rib 40 is effective to urge the push rod 41 upwardly to the end that the pawl 33 is rotated against the action of its biasing spring to release the firing pin carrier 24 to the action of the main spring 28, whereupon the carrier is driven forwardly and the tiring pin 22 is projected through the aperture 25 in the recoil plate 20 and into position for engagement with the primer of a safety cartridge 11 received in the firing chamber 18 so `as to detonate the same.

Access to the firing chamber 18 to permit loading and unloading is in the illustrative firearm accomplished by breaking the barrel assembly 14 with respect to the frame 12 so as to pivot the barrel assembly downwardly.

To hold the barrel assembly in normal or closed position ya spring biased detent 43 is provided in the frame 12 which is engageable in a complementally formed and juxtaposed recess 44 formed in the lower portion of the barrel assembly 14.

As shown, the barrel assembly includes an extractor 45 which is disposed at the rear end of the barrel assembly so that it engages the head of the cartridge. The extractor 45 is mounted for limited longitudinal movement upon an extractor rod 46 which in turn is spring biased so as to normally retain the extractor in forward position. The extractor 45 is operable to engage and urge the cartridge rearwardly, when the barrel assembly 14 is in open position with respect to the frame 12, a suiiicient distance to permit the cartridge head to be grasped by an operators lingers and removed from the firing chamber.

As hereinbefore noted the tiring chamber 18 of the illustrative irearm 10, as shown in FIGS 1 and 2, is defined in part by the barrel assembly 14 and in part by the recoil plate 20. More particularly, the rear portion of the liner 16 of the barrel assembly is utilized to receive the forward cylindrical portion of the casing of a round of ammunition and the portion of the projectile that extends therefrom. To define the rear portion of the chamber for receiving the head of the cartridge the recoil plate 20 has a forwardly opening recess 50 formed therein. It is into this recess that the firing pin aperture 25 opens in axial alinement with the liner 16 through which aperture the tiring pin 22 projects to a limited extent upon its movement into firing position for engagement with the cartridges primer. In carrying out the present inevntion provision is made whereby the tiring only of safety ammunition can be accomplished and the tiring of a standard or conventional ammunition is precluded. To this end the construction of the firing chamber is such that a conventional cartridge is positively positioned therein so that its primer is spaced forwardly of the tiring position of the tiring pin 22 so that it cannot be detonated, and a safety cartridge construction is provided wherein the primer is located for engagement and thus detonation by the firing pin.

To determine the seated or firing position of a round of ammunition the firing chamber 18 is formed with a transaxial surface for abutment by the rim of the cartridge of a round of ammunition inserted therein. In the firearms of FIGS. l and 2 the transaxial surface, indicated at 52, is defined by the rear end of the liner 16 and the bordering material of the barrel 14. In addition the construction insures abutment of a cartridge rim with the transaxial surface 52 when the tiring chamber is closed. Thus the recess in the recoil plate 20 is fashioned so that it has a transaxial dimension adjacent its forward end which is less than the rim diameter of a standard or conventional cartridge. As shown, the recess in the recoil plate 20 has its lower surface 50a formed so that it converges rearwardly from its forward open end toward the aperture 25. It will ybe apparent that upon movement of the barrel assembly 14 with respect to the frame 12, from an open or loading position into closed or tiring position, the head of a cartridge received therein is moved into engagement with the surface 50a of the recoil plate recess 50. The cartridge is urged forwardly thereby so that its rim abuts the rearwardly facing transaxial surface 52 where it is held until the firearm is broken open. In FIG. 2 the practice tirearm 10 is shown with a standard or conventional round of ammunition 54 disposed within the firing chamber 18. It will there be seen that the surface 50a is in engagement with the rearmost portion of the cartridge rim so that the forwardly facing s-urface of the cartridge rim is held against the rearwardly facing transaxial surface 52 of the forward portion of the ring chamber 18. Also the firing pin carrier 24 is in its forwardmost position and has carried the firing pin 22 into its tiring position. It will be seen that the forward end of the firing pin 22 and the primer S5 of the conventional cartridge 54 are spaced apart a predetermined distance as indicated by the letter S. As a result the primer 55 of the conventional cartridge 54 is not struck by the tiring pin and no detonation can occur.

In accordance with another aspect of the present in- Vention the safety cartridge 11 for use in the practice firearm 10 is provided. In carrying out this aspect of the invention, the safety cartridge 11 is of the type utilizing the explosive force only of a primer to propel its lightweight projectile and wherein the construction is such that its primer is disposed for engagement and detonation by the tiring pin 22. As shown in FIG. 4, the safety cartridge 11 is of the general type disclosed and claimed in my co-pending application Serial No. 359,647, tiled April 14, 1964. It includes a cartridge casing 56 yformed of plastic or other lightweight material having a bore 58 extending therethrough. 'I'he forward portion 58a of the bore is enlarged for the reception therein 0f a projectile 60. At its rear end the cartridge casing 56 is formed with a head 62 having a rim 63 for engagement with the transaxial surface 52 of the tiring chamber 18 which determines the seated or liring position of the cartridge within the tiring chamber. In the rear end of the head 62 the cartridge casing bore terminates in a recess 58h for receiving a primer 64. The recess SSb and the enlarged forward portion 58a of the cartridge bore 58 are interconnected by a bore portion 58C of reduced diameter for effecting venturi action upon the explosive force produced by detonation of the primer 64 for expelling the projectile 60 from the casing 56. In addition to utilizing only that force produced by the primer, the penetrative properties of the projectile 60 .are desirab-ly further reduced by fashioning it of lightweight resilient material such, for example, as rubber or relatively soft plastic. In order to stabilize the flight of the projectile 60, traveling at low velocity, it is formed with a plurality of symmetrically-spaced radial ns 65 that extend rearwardly from its body 66. This projectile construction has been found to effect a substantially flat trajectory for a range on the order of twenty-tive feet to thirty feet when propelled by the explosive force resulting `from detonation of a small primer.

The rim 63 of the round 11 of safety ammunition is cylindrical and extends rearwardly a distance substantially equal to the thickness of the rim of a conventional cartridge. To position its primer 64 `for engagement and detonation by the firing pin 22 the head 62 of the illustrative round 11 of safety ammunition is extended rearwardly so that the outer end of the primer is located a distance equal to or slightly greater than the predetermined distance S indicated in FIG. 2. In addition the cartridge head 62 is complementally formed for reception in the recess 50 of the recoil plate 20. As shown it is of frusto-conical shape. Thus, when a safety round so constructed is loaded into the practice firearm 10 the forward cylindrical portion of the cartridge casing 56 extends into the barrel liner 16, and when the barrel assembly 14 is moved into closed position with respect to the rframe 16, the outer conical surface of the head 62 is moved into engagement with the surface 50a of the recoil plate recess 50 whereby the cartridge is urged forwardly, with the forwardly facing surface of its rim 63 abutting the transaxial surface 52 of the firing charnber 18, and the practice round is positively positioned for firing. It will be apparent, too, that the peculiar rearward extension of the head 62 and its shape make the safety round readily distinguishable from other ammunition.

The present invention also contemplates the provision of an adapter for selectively converting a standard tirearm for practice use with safety ammunition as hereinbefore described so that only such ammunition can be fired when the standard firearm is so converted. It is also contemplated that the adapter can be readily removed and the firearm restored to its normal operating condition. In FIG. 3 there is shown a firearm 70 of the conventional revolver type. It includes a frame 72 which is equipped with a barrel 74, a pistol grip type handle 75, and a conventional firing mechanism including a hammer 76 mounting a firing pin 77 and a trigger 78 for releasing the hammer and firing pin for movement from cocked to firing positions. Intermediate its ends, the frame 72 is formed with an appropriate opening 79 for the reception of a cylinder (not shown). In carrying out this aspect of the present invention an adapter 80 is provided for alternative use in place of the conventional cylinder. The adapter 80 thus includes a block 82 defining a chamber 84 for the reception of the cylindrical forward end portion of the cartridge 56 of a round of safety ammunition 11. In the same manner as a conventional cylinder, the block 82 is adapted to be supported in place in the opening 79 of the frame 72 upon an extractor pin 86. The block 82 is coaxially counterbored to define a transaxial surface 88 about the rear end of the chamber 84 for engagement by the cartridge rim 63. The adapter also includes a recoil plate 90 which has a recess 92 to receive the rearwardly extended head 62 of the cartridge 11. The recoil plate 90 has an aperture 94 therein opening into the rear end of the recess 92 through which the firing pin 77 is projected for engagement with the primer 64 of the safety round 11. For purposes of loading and unloading, the recoil plate 90 is mounted for movement with respect to the adapter block 82. In this instance mounting is effected by way of a hinge 96.

From the foregoing it will be seen that the transaxial surface 88 of the adapter 80 is disposed in predetermined spaced relation to the tiring position of the firing pin 77. Thus, when the firearm is converted for safety ammunition use, a round of conventional ammunition inserted therein will be urged into seated position against the transaxial surface 88 when the recoil plate 90 is moved into operative position with respect to the block 82. Thus the primer of a conventional cartridge is held in spaced relation forwardly of the firing position of the firing pin so that detonation is precluded. For purposes of illustration the exemplary adapter has been shown with only one cartridge receiving chamber 84. It will be apparent, however, that it can be provided with a plurality of such chambers and can be fashioned of cylindrical shape and appropriately formed for rotary indexing movement by the revolving mechanism of the revolver to bring successive chambers into firing position.

I claim as my invention:

1. For use in a firearm having a firing pin movable a predetermined distance between cocked and tiring positions, the combination comprising means defining the forward portion of a firing chamber having a rearwardly facing surface for abutment by a cartridge rim to determine the seated position thereof, and a recoil plate having a recess therein defining the rearward portion of the firing chamber in axial alinement with said forward portion thereof, said recess having at least one transaxial dimension adjacent the forward end thereof less than the rim diameter of a conventional cartridge to insure abutment of its rim with said surface, and said recoil plate having an aperture therein opening into said recess and through which the firing pin is projected with its forward end stopping in its firing position a predetermined distance rearwardly of said surface which distance is substantially greater than the rim thickness of a conventional cartridge thereby locating the primer of a conventional cartridge in spaced relation to the firing pin so as to preclude firing of the same, and said recess being adapted to receive therein a rearwardly-extended, primer-supporting head portion of a safety cartridge in position for firing the same.

2. For use in a firearm of the type having a cylinder for receiving conventional ammunition and a firing pin movable a predetermined distance between cocked and firing positions, an adapter for alternative use in place of the cylinder, said adapter comprising, in combination, means defining a chamber for reception of a cartridge, means adjacent the rear end of said chamber for abutment by the rim of a cartridge to determine the seated position thereof, and a recoil plate having an aperture therein through which the tiring pin of the firearm can be projected with its forward end stopping in its firing position a predetermined distance rearwardly of said second mentioned means which distance is substantially greater than the rim thickness of a conventional cartridge, said recoil plate having a portion engageable with a cartridge received in said chamber for insuring abutment of the cartridge rim with said means and having a recess therein in alinement with said chamber into which said aperture opens, said recess being adapted to receive the rearwardly-extended primer-supporting head of a complementally formed safety cartridge whereby said safety cartridge can be fired but the primer of a conventional cartridge is located in spaced relation to the tiring pin in its firing position so as to preclude firing of the same.

3. For use in a firearm of the type having a cylinder for receiving conventional ammunition and a firing pin movable a predetermined distance between cocked and firing positions, an adapter for use in place of the cylinder, said adapter comprising, in combination, means defining an open-ended chamber for reception of a cartridge and having a transaxial surface bordering said chamber adjacent the rear end thereof for abutment by the rim of a cartridge to determine the seated position of the cartridge in said chamber, and a recoil plate mounted for movement into transaxial, juxtaposed, abutting relation with said means, said recoil plate having a recess therein in alinement with said chamber and having an aperture therein opening into said recess and through which the firing pin of the firearm can be projected with its forward end stopping in its tiring position a predetermined distance rearwardly of said surface which distance is substantially greater than the rim thickness of a conventional cartridge, said recess having a portion adjacent its forward end engageable with a cartridge received in said chamber for insuring abutment of the cartridge rim with said surface, and said recess being adapted to receive the rearwardly-extended primer-supporting head of a complementally formed safety cartridge whereby said safety cartridge can be fired but the primer of a conventional cartridge is located in spaced relation to the firing pin in its firing position so as to preclude firing of the same.

4. For use in a firearm having a firing pin movable a predetermined distance between cocked and firing positions, the combination comprising means defining the forward portion of a firing chamber having a rearwardly facing transaxial surface for abutment by a cartridge rim to determine the seated position thereof, and a recoil plate having a forwardly opening recess therein defining the rearward portion of the firing chamber in axial alignment with said forward portion thereof, said recoil plate including at least one surface defining a portion of said recess for engaging the rear end of a conventional cartridge inserted in said firing chamber and holding said cartridge against said transaxial surface so that the rear end of said cartridge is spaced a predetermined distance References Cited by the Examiner UNITED STATES PATENTS 732,540 6/1903 Garrison 42-77 Marble 42-69 Karner.

Gaidos 42-77 X Meador 102-43 Barnes et al. 102-38 Owens 42-77 Lahr 102--38 BENJAMIN A. BORCHELT, Primary Examiner. 

4. FOR USE IN A FIREARM HAVING A FIRING PIN MOVABLE A PREDETERMINED DISTANCE BETWEEN COCKED AND FIRING POSITIONS, THE COMBINATION COMPRISING MEANS DEFINING THE FORWARD PORTION OF A FIRING CHAMBER HAVING A REARWARDLY FACING TRANSAXIAL SURFACE FOR ABUTMENT BY A CARTRIDGE RIM TO DETERMINE THE SEATED POSITION THEREOF, AND A RECOIL PLATE HAVING A FORWARDLY OPENING RECESS THEREIN DEFINING THE REARWARD PORTION OF THE FIRING CHAMBER IN AXIAL ALIGNMENT WITH SAID FORWARD PORTION THEREOF, SAID RECOIL PLATE INCLUDING AT LEAST ONE SURFACE DEFINING A PORTION OF SAID RECESS FOR ENGAGING THE REAR END OF A CONVENTIONAL CARTRIDGE INSERTED IN SAID FIRING CHAMBER AND HOLDING SAID CARTRIDGE AGAINST SAID TRANSAXIAL SURFACE SO THAT THE REAR END OF SAID CARTRIDGE IS SPACED A PREDETERMINED DISTANCE FORWARDLY OF THE FIRING POSITION OF THE FIRING PIN, SAID SURFACE OF THE RECOIL PLATE BEING ADAPTED TO COOPERATE WITH A COMPLEMENTALLY FORMED SAFETY CARTRIDGE TO PERMIT THE REAR END OF THE SAFETY CARTRIDGE TO PROJECT REARWARDLY WITHIN SAID RECESS TO THE FIRING POSITION OF SAID FIRING PIN. 